Unverified Commit 9d180ec9 authored by Steven Fackler's avatar Steven Fackler Committed by GitHub
Browse files

Merge pull request #1973 from anpage/bn_mod_sqrt 

bn: Add mod_sqrt
parents ee44daf4 fa460ea6

openssl-sys/src/handwritten/bn.rs

+7 −0
Original line number Diff line number Diff line
@@ -73,6 +73,13 @@ extern "C" { 
        m: *const BIGNUM,

        ctx: *mut BN_CTX,

    ) -> c_int;

    #[cfg(ossl110)]

    pub fn BN_mod_sqrt(

        ret: *mut BIGNUM,

        a: *const BIGNUM,

        p: *const BIGNUM,

        ctx: *mut BN_CTX,

    ) -> *mut BIGNUM;



    pub fn BN_mod_word(r: *const BIGNUM, w: BN_ULONG) -> BN_ULONG;

    pub fn BN_div_word(r: *mut BIGNUM, w: BN_ULONG) -> BN_ULONG;

openssl/src/bn.rs

+33 −0
Original line number Diff line number Diff line
@@ -639,6 +639,26 @@ impl BigNumRef { 
        }

    }



    /// Places into `self` the modular square root of `a` such that `self^2 = a (mod p)`

    #[corresponds(BN_mod_sqrt)]

    #[cfg(ossl110)]

    pub fn mod_sqrt(

        &mut self,

        a: &BigNumRef,

        p: &BigNumRef,

        ctx: &mut BigNumContextRef,

    ) -> Result<(), ErrorStack> {

        unsafe {

            cvt_p(ffi::BN_mod_sqrt(

                self.as_ptr(),

                a.as_ptr(),

                p.as_ptr(),

                ctx.as_ptr(),

            ))

            .map(|_| ())

        }

    }



    /// Places the result of `a^p` in `self`.

    #[corresponds(BN_exp)]

    pub fn exp(
@@ -1455,4 +1475,17 @@ mod tests { 
        b.set_const_time();

        assert!(b.is_const_time())

    }



    #[cfg(ossl110)]

    #[test]

    fn test_mod_sqrt() {

        let mut ctx = BigNumContext::new().unwrap();



        let s = BigNum::from_hex_str("47A8DD7626B9908C80ACD7E0D3344D69").unwrap();

        let p = BigNum::from_hex_str("81EF47265B58BCE5").unwrap();

        let mut out = BigNum::new().unwrap();



        out.mod_sqrt(&s, &p, &mut ctx).unwrap();

        assert_eq!(out, BigNum::from_hex_str("7C6D179E19B97BDD").unwrap());

    }

}